United Nations Environment Programme

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Tool 15: Future vehicles and fuels



How far can technology take us?

Making sustainable transport a reality will place huge demands on vehicle and fuel technologies, especially if the transport sector continues to grow.


A sustainable transport future means that emissions of local and regional air pollutants must be close to zero per kilometre driven, and that net emissions of greenhouse gases must be close to zero. In order to achieve a sustainable transport system, a top-of-the-line vehicle in 2050 will face the following demands:

Toyota Prius Hybrid Photo: Toyota


  1. Close to zero emissions of pollutants
  2. Use of renewable fuels that emit close to zero net emission of carbon dioxide (CO2)
  3. Substantially more energy efficiency than today’s vehicles (at least twice as much)

Close to zero emissions. Emissions regulations are getting stricter every year. As transport volumes continue to grow and as awareness of the health effects of air pollution increases, demands for cleaner vehicles will continue. Euro V (Europe) and Tier II (US) standards will certainly be followed by Euro VI and Euro VII or Tier III respectively.


Use of renewable fuels. Oil and other non-renewable energy sources will not last forever. Moreover, using all of our resources would effectively release all of the carbon locked in the ground into the atmosphere, destroying our climate system. Renewable fuels do not emit any net emissions of CO2, do not contribute to global warming, and will not “run out” if used sustainably.


Substantially more energy-efficient vehicles. Renewable energy sources are expensive (e.g. solar) or scarce, but can not be depleted (e.g. biomass). Highly efficient vehicles use very little fuel, and provide an excellent market for renewable energy, making it more affordable.


What are the options?

Given our current technological situation, the most ideal long-term option is to use solar power (which is renewable and unlimited) to turn hydrogen into electricity, which can power fuel cell electric vehicles (FCEV). This option has zero emissions; fuel cells that derive their energy from hydrogen emit only water.

Below is an illustration of future “energy source-fuel-vehicle” combinations that are all highly energy efficient and low polluting.

Figure 13: Future energy sources-fuel-vehicle combinations that are highly efficient, low-polluting and use renewable energy.


Hydrogen-fuelled fuel cell vehicles are not the only option; electric vehicles and hybrid vehicles fuelled with a renewable fuel are still viable and interesting options for the future.


 What are the barriers?

The ideal solution – i.e. solar powered fuel cells – requires a number of technical components that are still not fully developed and are very expensive. Today, the combination “solar power-hydrogen-fuel cell” is technically immature and extremely costly. Nonetheless, prototype fuel cell vehicles have been manufactured and are generally regarded as ideal long-term options. However, progress has been slower than first anticipated.


The fuel cell engine for a vehicle is today expected to cost over $40,000; this cost needs to decrease to at least $2000 in order to be competitive. Fuel cell vehicles combined with solar power produced hydrogen are expected to be available in the commercial market in the next 10-25 years, provided development is successful.


Hybrid electric vehicles (HEVs) are available today (see Tool 13), although the potential for improvement is still great. The market share for HEVs is growing rapidly, and this is expected to continue in the future. An interesting future option is also "plug-in hybrids" that can be charged with electricity from the electricity grid. Further battery development is needed to make this a reality.


First generation biofuels are also currently available (see Tool 14 and the glossary) and are produced from sugar cane, corn, grain and rapeseed. The second generation of biofuels are currently under development and are expected to be commercially available within 10 years. They will be produced from non-food crops (such as wood and its byproducts) or inedible waste biomass (such as stalks of wheat and corn). This could eventually make the fuels cheaper. In addition, such biofuels would not impact on the price of food and, when waste biomass is used, no extra land would be required to grow fuel crops, thus avoiding potential deforestation. Third generation biofuels could potentially be made from algae, although this is still in the early developmental phase.

What can you do now?
Most of the promising options for the future are still under development; however, this does not mean that you, as a fleet manger, can or should sit and wait. Taking a proactive stance and being “an early adopter” of technologies as they become available on the market will give you crucial experience before that of your competitors, and will also contribute to a positive environmental image for your company. There are also considerable cost savings that can be enjoyed from the use of new technologies. Hybrid technologies and biofuels already exist on the market and much can be gained and learned through adoption of these technologies (see the DHL example).

Green Procurement
You can already start to clean up your fleet, if you ensure that the fuel efficiency and air pollution specifications of potential vehicles will be important considerations in the procurement process. When buying new vehicles it is recommended to calculate the Total Costs of Ownership -which includes the expected fuel and maintenance costs- for all vehicles. Additionally, low emissions of air pollution should be considered as an advantage.

There are various websites available to assist in this process. Both US EPA (US Environmental Protection Agency) and the FIA Foundation measure and rate the fuel efficiency and the environmental pollution (like SOx, NOx, particulate matter, etc.) of various vehicles. Both ratings are published on their websites, together with recommendations on the best environmental performing vehicles in various vehicle categories.

For more information and vehicle classifications >>

  • US EPA Green Vehicles Guide, http://www.epa.gov/greenvehicles

  • FIA Ecotest Programme, www.ecotest.eu